Operating mechanism for discharge lamps



Nov. 30, 1943. F. D. BRYANT OPERATING MECHANISM FOR DISCHARGE LAMPSFiled July 21, 1942 2 Sheets-Sheet l yams,

Inventor: FT" ank D. Br 5 JV 6. J

y ;is Attorney Nov. 30, 1943. F, D.- BRYANT OPERATING MECHANISM FORDISCHARGE LAMPS Filed July 21, 1942 2 Sheets-Sheet 2 Inventof Frank I).Br

b f/ 6i y mttorney Patented Nov. 30, 1943 UNPTED STATES PATENT OFFICE.

2,335,640 OPERATING MECHAHQM FOB DISCHARGE LAMPS Frank D. Bryant,Syracuse, N. Y.,

General Electric New York nssignor to Company, a corporation ofApplication July 21, 1042, sens: No. 451,698 3 Claims. (cL zoo-s) Myinvention relates to an operatingmecha of the switch mechanism lookingalong the line |l of Fig. 3; Fig. 2 is another view of the switchmechanism looking along the line 22 of Fig. 3; Fig. 3 is an end view ofthe switch; Fig. 4 is an exploded view showing the switch elements,Figs. 5 and 6 illustrate a portion of the switch mechanism in variousoperating positions, and Fig. 7 is a diagrammatic view showing one wayof con-' necting my switch into an operating circuit for a fluorescentlamp.

Referring to the drawings, the switch mechanisnrdesignated generally as'I0 is housed within a casing l I of any suitable" insulating material,such as a molded plastic. As shown in..Fig. 3, the casing is made intwoparts held' together around the mechanism bybolts i2, Within-thecasing is a supporting .yoke l3 mounted on the end of a hollow. stud llwhich receives and guides a pull chain ii for manually operating theswitch mechanism.

The two arms ot the yoke 13 are each provided with integrally formedspaced projections I! which act as supports for, spaced insulating disksor rings I8 and I 9. The disks are formed with openings while theprojections are likewise formed with openings 2| both oi which receivefastening bolts held in position by nuts 23. The disks l8 and I! areformed of suitable low cost insulating material, such as sheet fiber,from I which they may be punched. Each disk is formed as an annulusprovided with a diametrical web 24 formed with an opening 25 forreceiving a pivot'or arbor 26. In mounted position, the disks l8 and I!are spaced apart on opposite sides of the yoke, as shown in Fig. 3, andthe arbor 26 extends between the members to form a pivot for the'movablepart or the switch mechanism to be described presently.

The web 24 of the disk l8 carries a contact member 21 in the form of acurved spring blade which extends outwardly from the web to a positionadjacent the rim of the annulus. Electrical connection to the contactmember is made possible through a screw 28 to which a conductor 28 isconnected, as shown by Fig. 1. On the oth- .ried by a plate turn, isrotatably mounted on the pivot 26. shorting member is whichenxases erside of the disk I 8 at a point opposite the contact 21 is anothercontact member 30 which is fastened to the rim of the disk by a rivet II. The contact member Ill likewise has a curved portion located adjacentthe with the contact member 21 forms an electrical circuit when aconducting member is passed between them. A Jumper 32 is electricallyconnected to the contact 30 through the rivet 3 I; this Jumper carries aterminal screw 33 for making an electrical connection with a conductor3|. Electrical connection between the contacts 21 and 30 is eilected bymeans of a shorting member II car- 36 of insulating material which, in

The base portion or the fastened to the plate 38 in any suitable manner,as by rivets 31 while that portion of the member the contacts is offsetfrom the plate and is--reversely bent to U-shape so that it easilypasses between the contact members 21 and II and makes contact with eachblade to complete an electrical circuit .therethrough. A washer 3! ofinsulating material separates the plate II from the disk I! and preventsbinding so that the plate rotates easily.

The web 24 of the disk llalso carries a contact member 40 diametricallyopposite the contact 21. The contact lll is formed as a curved springblade, the same as the contact 21, and extends outwardly from the web toa position adiacent the rim of the annulus; it carries .a terminal screw4| to which an electrical connection is made as by a conductor 42. ,Anadditional spring blade contact 43 is carried by the disk I! on the sideopposite the contact M. The contacts 40 and II are adapted to be bridgedby a shorting member 44 carried by the rotatable plate ll. Inallrespects, the shorting member ll corresponds to the previouslymentioned shorting member 35 and is similarly mounted on the plate.However, it is insulated from the shorting member II by a portion of thesupporting plate 38. Contact member 43 is fastened to the rim of thedisk by a rivet 43 which likewise holds in position a conducting Jumper45 carrying a terminal screw 48.. A con-. ductor 41 provides anelectrical connection with the terminal screw.

The other disk I! is likewise provided with contact members comprisingspaced spring blades it and 49. Each blade is secured to the web 2| inany suitable manner, as by a rivet i0 and is curved outwardly to a pointadjacent the rim of opposite each other on the rim of the disk andtogether same side of the disk. As shownby Fig. 2, the

. contact 48 carries a terminal screw for receiving a conductor 52 whilethe contact 49 likewise carries a terminal screw 53 to which a conductor54 is connected.

Mounted for rotation on pivot 26 is a carrier or disk 55 of insulatingmaterial which carries a contact or shorting member 56 adapted to engagethe fixed contact blades 48 and 49 for establishing a circuittherebetween. To this end, the shorting member is provided with opposedarms 51 which ride over the surfaces of the fixed contact members as thecarrier is rotated. The shorting member is secured to the carrier in anysuitable manner, as by rivets 58 and the center portion is hollowed out,as indicated at 59 so that it is electrically insulated from the pivot26. A washer 68 of insulating material is disposed between the disk l9and the rotatable carrier 55 so that the latter rotates freely.

The disks l8 and 19 are mounted on the yoke 13 in the manner alreadydescribed and the carrier 55 and plate 36 are mounted for rotationbetween them with the contacts on the rotatable members cooperating withthe corresponding fixed contacts carried by the disks. Both the plate 36and carrier 55 are provided with an annular flange 6| which, when theseelements are assembled together, provides a trough or raceway for thepull chain I5 of the operating mechanism now to be described.

As shown in Figs. 3 and 5, the pull chain extends around the perimetersof the plate 36 and carrier 55 and is connected to one end of a coiledspring 62 by a link 63. At itsotherend,

' the spring is secured to a clip 64 struck up from the yoke IS. A pin65 is carried by the link and, in assembled position, is seated in agroove or opening 66 formed in the edge of the plate 36.

61. The operation just described means that upon continued pulls on thechain, the plate 36 and its associated contacts are moved to circuitclosing position and then released to initial open position but that thecarrier 55 and shorting contact 56 are moved in step-by-step movement toopen and closed position, alternately.

As shown by Figs. 3 and 4, the assembled switch mechanism is held inposition in the housing H by bolts 69 extending through opening 10 inthe disks l8 and i9 and threaded to bosses 11 up- The pin is alsoadapted to cooperate with one.-

way cam surfaces 61 formed at spaced points around the perimeter of thedisk or carrier 55 and constituting a means to form a ratchet connectionwith the pin 65. In the instant case,

four of such cam surfaces are provided correspending to four positionsof the shorting member 51 two of which correspond to the "011 and onpositions of the switch, respectively.

Initially; one of the cam surfaces 61 will be in alignment with thegroove 61, as shown in Fig.

5, and the pin 65 will be seated therein. The contacts 35 and 44 will bein alignment with the arms 51 of the shorting contact 56. This meansthat a pull on chain 15 against the action of spring 62 will rotate theplate and carrier 55 through an angle of 90 so that the contacts 35 and44 are moved to position between the fixed contacts on disk I8 andsimultaneously the arms 61 engage the fixed contacts. 48 and 49 on diskwise direction, in the showings of Figs. 4 and 5 is limited byengagement of the offset contact 35 with the edge of the web 24 of thedisk 18. Upon release of the pull chain. the spring 62 will rection.Since the pin 65 remains in groove 68, the plate 36 will be returned toits original position but as for the carrier 55, the pin will slide oflthe one-way cam surfaces onto the perimeter I9.. Rotation of theelements in a counterclockg0 move certain of the elements in theopposite di- 5 ofthe carrier, as shown by Fig. 6, and will be 7 returnedfor engagement with the next succeedingcam surface 61. During thisoperation, re-

turn movement of the carrier 55 is prevented by a spring blade 68mounted on the yoke and which engages an app p iate one of the camsurfaces 76 standing from a wall of the housing. One manner in which theswitch may be connected into an operating circuit for fluorescent lampswill now be described.

Referring to Fig. 1, I have shown two fluorescent lamps 13 and 14operatively connected in circuit with my switch and with a ballast B ofa type now available commercially. The ballast is provided with areactor 15 having a lagging power factor connected to lamp 18 while asecond reactor 16 having a leading power factor, due to the capacitor11, is connected to the other lamp 14. A compensator 18in the form of areactor adds inductance to the heating circuit of the second lamp toinsure quick starting. The ballast just described forms no part of myinvention since, as aforementioned, it is of a type now commerciallyavailable. Flourescent lamp 13 is provided with heating filaments 19 andat opposite ends thereof while the lamp 16 is:

likewise provided with spaced filaments 8i and 82. The manner in whichthe switch operates to start the lamps will now be described, it beingnoted that in the diagrammatic showing of Fig. '1 the switch is in startposition with the contacts on the rotatable members 56 and 55 inengagement with the corresponding fixed contacts carried by the disks l8and 19.

When the chain 15 has been pulled downwardly to move the contacts on therotatable member to circuit closing position, current flows from oneside 83 of an alternating current supply line to the reactors 15 and 16of the ballast. Current from reactor 15 flows through conductor 84 tofilament 86 at one end of the lamp 13, then by conductor 34 to fixedcontact 85, through contact 35 on the rotatable carrier 35 to fixedcontact 21, then by conductor 28 to the filament 19 at the other end ofthe lamp, then by conductor 52, fixed contact 68, movable shortingmember 56, fixed contact 49 and conductor 54 to the other side 85 of thesupply line. Simultaneously, current fiows from reactor 16 by aconductor 86 to filament 82 at one end of the lamp 14, then by conductor42 to fixed contact 46' through movable contact 64, fixed contact 43,conductor 41 to the compensator 18, then by a conductor 81 to filament8| at the other end of the lamp, by conductor 88 to conductor 52 andthen through fixed contact 48, shorting member 56, fixed contact 49 andconductor 54 to the other side 85 of the supply line.

It should be manifest that the arrangement is such that as long as thechain 15 is held in pulled-down position, current will flow through theelectrodes of both fluorescent lamps in the manner just described topreheat them. Usually, this preheating time is on the order of one tofive seconds and the chain should be held pulled down for this period oftime. Upon release of the operating chain l5, the carrier 55 and shorting member 56 will remain incircuit closing position but the plate 55and contacts 35 and 65 will be returned to their initial open position:quick pull on the chain l so that I used with two fluorescent so thatthe circuits through the fixed contacts "-30 and 40-, respectively, willbe opened. This opens the circuits across the filaments of the lamps sothat the reactors and 18 provide an inductive kick causing a glowdischarge to v strike between the filaments of each lamp, lighting thelamp. When this occurs, the circuit through the operating mechanism isas follows.

Current fiows from reactor 15 through conductor 84 to the filament 80across the glow discharge in lamp 1; to filament 15, then by conductor52, contact 48, shorting member 58, contact l9 and conductor 54 to theother side of the supply line. Simultaneously, current flows Jroinreactor 16 through conductor 86 to filament 82, then across the glowdischarge in lamp M to filament 8|, conductor 80, conductor 52, contact4|, shorting member 56, contact l9 and 'conductor II to the other sideof the supply line.

When it is desired to turn on the lamps, the operating chain I5 is againpulled downwardly so that the pin 65 engaging in the next succeeding camsurface 61 moves the shorting member I to circuit opening positionbetween the contacts 48 and 49. Even though the rotatable conoil by asimple operation of the pull chain I 5' which operates the switchmechanism in sequence to on and "cit" positions. When the switch ispulled on, it is only necessary to hold the pull chain down for a fewseconds to effect preheating of the lamp filaments. Should the lamps notlight on the first operation of the switch mechanism, the mechanism maybe quickly moved through the "oil!" position by a the next pull inposition to my switch as being lamps, it should be manifest that theswitch will operate equally as well with only a single fluorescent lampsimply by omitting the connections to one oi" the pairs or contacts 21-"or -43. The mechanism will 88- place the mechanism start the lamps.

While I have illustrated is or a type which is welladapted for use inordinary pull chain sockets such as are used to a considerable extent infioor lamps.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A switch mechanism comprising an insulating casing, two axiallyspaced insulating plates with contacts thereon secured in the casing, afirst and a second disk with shorting members thereon for cooperationwith said contacts being rotatably supported between the insulatingplates and forming a raceway between them, and means for rotating thedisks to effect electrical connection between the contacts and therespective shorting members comprising a pullchain engaging the raceway,a spring connecting the chain to the casing, a pin fastened to the chainandmeans on the first disk forming a positive drive between the .pin andthe first disk and means on the second disk forming a ratchet connectionbetween the pin and the second disk to rotate both disks upon pulling ofthe chain and to cause return of the first disk to its initial positionupon subsequent release of the chain. 2. A switch for operating adischarge lamp having spaced filaments comprising an insulating casing,first and second pairs of contacts secured to the casing, first andsecond disks each with a shorting member thereon for cooperation withthe respective pairs of contacts, the first disk having an opening, thesecond disk having circumferentially spaced cam surfaces, spring meansfor biasing the first disk into a fixed angular position, and means forrotating both disks against said biasing spring to establish connectionbetween the pairs of contacts and the respective shorting members andsubsequently to cause the first disk to return to its original positionby action of the spring, said means including a pin projecting throughsaid opening and engaging said cam surfaces.

3. A switch mechanism comprising a casing, first and second pairs ofcontacts secured to the casing, first and second disks with shortingmembers thereon for cooperation with the respective pairs of contacts,

a pullchain connected to the casing, a pin secured j to the chain,

positive connecting'means between the pin and the first disk and ratchetconnecting means between'the pin and the second disk.

FRANK D. BRYANT.

means rotatably supporting, the disks within the casing, said diskshaving

